A polymer electrolyte fuel cells (PEFC) using a proton conductive solid polymer membrane works at a lower temperature than other types of fuel cells, for example, solid oxide fuel cells and molten carbonate fuel cells. For this reason, the polymer electrolyte fuel cell is expected as a stationary power source and a power source for moving bodies such as motor vehicles, and it has been started to put the polymer electrolyte fuel cells to practical use as well.
In general, an expensive metal catalyst typified by Pt (platinum) or a Pt alloy has been used in such a polymer electrolyte fuel cell. In addition, a carbon carrier having a large specific surface area or a doped carbon carrier has been used as a carrier supporting a metal catalyst in order to highly support and disperse the metal catalyst. However, the conventional carbon carrier has not been able to sufficiently achieve activity of supported platinum while taking full advantage of characteristics of a carbon material.
In order to solve the above problem, for example, Patent Literature 1 discloses an electrode catalyst for fuel cell having platinum or a platinum alloy supported on a carbon alloy fine particle (carbon substrate) to be doped with at least either of a nitrogen atom or a boron atom and having an average particle size of 45 μm or less. The Patent Literature 1 discloses that the catalyst supporting platinum exhibits high activity since the carbon alloy fine particle described therein has an increased number of electronically and chemically active edge surfaces.